DescriptionThere are "+" and "-" marks on the back of the charger, which correspond to the positive and negtive. Or you can pull out the cable and make it a independent switch. Drill a hole of diameter of 3cm, and put this charger in, and tighten it.

High current of 5V 2.1A+2.1A(Totally 4.2A). More safe and fast charging.Blue LED illuminated USB charging. Fits any 12V-24V Car, Motorcycle, ect.Dual USB design which can charge two devices at the same time.Can charging your mobile phone, tablet, GPS, digital camera and so on [ Shop Now ]